Method for producing space-dyed textured yarn

ABSTRACT

The method of the present invention permits the production of small denier space-dyed yarns on coarse gauge or cut knitting machines of the type normally used in producing a prefabric for use in the production of large denier space-dyed yarns. To this end, two or more yarns are fed to the needles of the knitting machine and the yarns are alternately twisted together in one direction and then in the opposite direction while the yarns are simultaneously knit by the needles so that the yarns are alternately twisted together in opposite directions in the knit prefabric. The twisted together yarns in the prefabric insure that each yarn will be subjected to the same application of color when patterns are applied to the prefabric. The alternate twisting of the yarns also permits easy separation of the yarns as the knit prefabric is unravelled. Twist imparting means is applied to the knitting machine for twisting the pair of yarns together in one direction and then in the opposite direction as the yarns are fed to the hooks of the needles.

United States Patent 11 1 McWhirter et al.

[ Nov. 18, 1975 METHOD FOR PRODUCING SPACE-DYED TEXTURED YARN [73] Assignee: Pharr Yarns, Incorporated,

McAdenville, N.C.

22 Filed: Oct. 15,, 1974 [21] Appl. No.: 514,652

Related US. Application Data [62] Division of Ser. No. 349,426. April 9, 1973, Pat. No.

Primary ExaminerRobert R. Mackey Attorney, Agent, or Firm-Parrott, Bel], Seltzer, Park & Gibson [5 ABSTRACT The method of the present invention permits the production of small denier space-dyed yarns on coarse gauge or cut knitting machines of the type normally used in producing a prefabric for use in the production of large denier space-dyed yams. To this end, two or more yarns are fed to the needles of the knitting machine and the yarns are alternately twisted together 3,861,176. in one direction and then in the opposite direction while the yarns are simultaneously knit by the needles [52] US. Cl. 28/7216; 28/74 R so that the yarns are alternately twisted together in op- [51] Int. Cl. D04B 19/00 posite directions in the knit prefabric. The twisted to- [58] Field of Search 28/7216, 74 R; 66/136, gether yarns in the prefabric insure that each yam will 66/137, 126 be subjected to the same application of color when 9 patterns are applied to the prefabric. The alternate [56] References Cited twisting of the yarns also permits easy separation of UNITED STATES PATENTS the yarns as the knit prefabric is unravelled. Twist im- 3.0'12.303 12/1961 Whitaker et a1. 28/7216 l l apphed to the klmtmg e for 3,720,984 3/1923 Roberson, Jr 28/7216 f f g Palm]? g together 3 one dlrect'ofn 5 t t t I t FOREIGN PATENTS oR APPLICATIONS fi gl ifigi i gj as yams are e 0 46,199 3/1889 Germany 66/137 197,891 5/1889 Switzerland 66/137 2 Claims 9 Drawmg Flgures ALTERNATEY APPLY CoLoe H S UNEAV EL ATwksriNe J PATYEELNS To l\ EAT ET p FABRC SE 53 V Pres: FABRIC V7 Pei-z FABRIC ztlA Up YARNS A SEPARATELY FlGS. Z M: FIG. 5 Fie F155 US. Patent Nov. 18, 1975 Sheet 1 of2 3,919,749

ALTERNATEY APPLY Come UNEAV EL TWI5T\NG- J PATTERNS To HEAT SET P25 FABRJC ND KNlTHNGr .V/ PREFABRKC Pas FABRIC i'IAKE UP YARNS PRE FABPJC SEPARATELY F165. 24: FIG. 5 F\G-.4 FIG-.5

\N'HNG STA'HON PR\NT\NG- STmoN U.. Patent Nov. 18,1975 Sheet2of2 3,919,749

METHOD FOR PRODUCING SPACE-DYED TEXTURED YARN This is a division of application Ser. No. 349,426, filed Apr. 9, 1973, now US. Pat. No. 3,861,176 granted Jan. 21, 1975.

This invention relates generally to a method for twist-' ing together and knitting yarns to form a prefabric which is used in producing space-dyed yarns and more particularly to such a method which permits the production of small denier space-dyed yarns on knitting machines intended for knitting a prefabric for use in producing large denier space-dyed yarns.

The usual method employed in producing space-dyed yarns includes knitting a single end of yarn on a knitting machine of the particular gauge or cut adapted to knit the particular denier of yarn to form what is normally referred to as a prefabric, applying color patterns to the prefabric, heat-setting the prefabric, and then unravelling the prefabric and collecting the space-dyed yarn. This type of space-dyed yarn is normally used in various types of fabrics, primarily as the tufting yarn in carpets and the like. This method of producing space-dyed yarn is disclosed in the Whitaker et al US. Pat. No. 3,012,303, issued Dec. 12, 1961.

Up to the present time, most space-dyed yarns used in tufted carpets have been rather large, within the range of approximately 2,300 to 5,200 denier. Recently, the demand has increased for smaller denier space-dyed yarns of from approximately 1,150 to 2,600 denier. While it is possible to knit this smaller size of yarn on a knitting machine of the gauge or cut adapted to knit larger size yarn, it is not economically feasible and does not produce the best quality of space-dyed yarn. When the smaller denier yarn is knit on a heavy gauge machine, the resulting prefabric is very open and sleazy so that the printing of the color patterns on the prefabric has a different effect than when printed on a fairly thick and relatively heavy prefabric. Also, the time required in the knitting, heat-setting and unravelling of the small denier yarn is the same as the time required to perform these steps and form large denier space-dyed yarn, however, the yield in pounds of small denier space-dyed yarn is substantially one-half the yield when producing heavy denier space-dyed yarn.

With the foregoing in mind, it is an object of the present invention to provide a method for twisting together and knitting yarns to form a prefabric which is used in producing small denier space-dyed yarns in an economical manner and for maintaining uniformity high quality in the space-dyed yarns.

In accordance with the method of the present invention, two or more small denier yarns are simultaneously knitted while being alternatively twisted together in first one direction and then in the opposite direction so that the yarns are alternately twisted together in opposite directions in the knit prefabric, color patterns are applied to the prefabric and heat-set, and the prefabric is unravelled while separating and taking up the yarns in separate packages.

In accordance with the apparatus of the present invention, twist imparting means is applied to the knitting machine for alternately twisting the yarns together in one direction and then in the opposite direction as the yarns are fed to and through the feed finger of the knitting machine and to the hooks of the needles. The twist imparting means is applied to a flat V-bed knitting machine and includes a rotating sprocket having yarn guide openings therein and being supported for alternate rotation in opposite directions as the sprocket is moved from one end of the knitting machine to the other. The sprocket is rotated by means of a sprocket chain engaging the teeth of the sprocket to impart rotation to the sprocket in one direction as it moves in one direction along the knitting machine and to impart reverse rotation thereto as it moves in the opposite direction. Since the yarns are alternatively twisted together in the opposite directions in the knit fabric, they may be easily separated and taken up separately as the prefabric is unravelled.

Other objects and advantages will appear as the description proceeds when taken in connection with the accompanying drawings, in which:

FIG. 1 is a block diagram schematically illustrating the steps carried out in the present method of producing space-dyed yarns;

FIG. 2 is a transverse vertical sectional view through the needle beds of a V-bed knitting machine and illustrating the manner in which the stitch cams engage the needles carried thereby in the knitting of the prefabric;

FIG. 3 is a schematic illustration of the application of the color patterns to the prefabric;

FIG. 4 is a schematic illustration of the heat-setting of the prefabric;

FIG. 5 is a schematic illustration of the unravelling of the prefabric, separating the reversely twisted yarns, and taking up the yarns on separate packages;

FIG. 6 is a fragmentary isometric view of one end portion of the V-bed knitting machine and illustrating the twist imparting sprocket applied thereto;

FIG. 7 is an enlarged fragmentary vertical sectional view taken substantially along the lines 77 in FIG. 6;

FIG. 8 is an enlarged plan view of the twist imparting sprocket; and

FIG. 9 is an enlarged fragmentary view of a portion of the prefabric, schematically illustrating the manner in which the two yarns are alternately twisted together in opposite directions in the prefabric.

The method of producing space-dyed yarns in accordance with the present invention is illustrated as including the knitting of prefabric on a flat V-bed type of knitting machine and with the needles of both knitting beds being operated to form a flat rib fabric. However, it is to be understood that other types of knitting machines may be utilized and a tubular fabric may be knit on the V-bed machine illustrated or on a circular type machine, if desired. As has been stated, it has been the usual practice to knit a single end of relatively heavy denier yarn on a heavy or coarse gauge or cut knitting machine, apply color patterns to the prefabric, heat-set the prefabric, and then unravel the prefabric so that the unravelled yarn has irregularly spaced colored or dyed portions therealong, and is generally referred to as space-dyed yarn.

In accordance with the present invention, as illustrated in FIG. 1, two or more relatively fine denier yarns are alternately twisted together in first one direction and then in the opposite direction as they are fed to the needles of the knitting machine so that the yarns are alternately twisted in opposite directions in the prefabric. Color patterns are then applied to the prefabric and heat-set. The yarns are unravelled from the prefabric and taken up separately so that two or more spacedyed yarns of uniform quality are simultaneously produced. It is not possible to simultaneously produce two or more space-dyed yarns of uniform quality without twisting the yarns together in first one direction and then in the opposite direction as they are knit in the prefabric because two or more yarns simultaneously fed to the needles in side-by-side relationship have a tendency to maintain substantially the same relationship throughout the prefabric with the result that the yarn which is predominantly exposed on the face of the prefabric will receive a heavier application of the color pattern than the yarn which remains primarily on the inner portion of the prefabric. This will produce noticeable streaks in any final fabric formed of the spacedyed yarns, particularly tufted carpeting.

As illustrated in FIGS. 2 and 6, the yarns Y-l and Y-2 are twisted together first in one direction and then in the opposite direction, by means to be presently described, as they are directed downwardly through the guide hole in the lower end of a yarn feed finger of a flat V-bed knitting machine including needle beds 1 1 and 12. Banks of latch needles N are supported for longitudinal movement in each of the needle beds 11, 12 and are successively raised to pick up the yarns and then lowered to form successive courses of stitch loops in a one-by-one ribbed prefabric F. Stitch earns 13, 14 engage the butts of the needles N in each needle bed 11, 12 and successively move the needles through a stitch forming cycle as the stitch cams are moved back and forth along the needle beds 11, 12 by stitch cam support plates 15, 16 and in a manner to be presently described.

Suitable color patterns are then applied to the prefabric. The color patterns may be applied to one or both sides of the prefabric and the color patterns are schematically illustrated in FIG. 3 as being applied by spaced apart printing stations indicated at 20 and 21. The prefabric F is then heat-set, such as by passing the same through a heating oven, indicated at in FIG. 4. The heat-set and printed prefabric F is then unravelled to provide space-dyed yarns Y-l and Y-2 which are separated and wound onto separate take-up packages 26 and 27.

Referring to FIG. 6, it will be noted that the stitch cam support plates 15, 16 are supported for sliding movement on respective guide bars 30, 31 and are interconnected by a bridging member 32. Back and forth reciprocating movement is imparted to the switch cams l3, l4 and stitch cam support plates 15, 16 by a drive chain 33 which also imparts back and forth movement to a feed finger drive bracket 34, suitably connected to the bridging member 32. The drive bracket 34 imparts movement to the feed finger 10 which is supported adjacent its upper end in a slide block 36 supported on guide bars 37. Opposite ends of the knitting machine, only one end of which is shown in FIG. 6, are provided with a support plate 40 for supporting opposite ends of the guide bars 30, 31 and an upwardly extending support arm 41 which supports the guide bars 37. The prefabric F is drawn downwardly by suitable take-up rolls 42 and deposited in a suitable container or the like. The portions of the knitting machine heretofore described are conventional parts of a Universal V-bed knitting machine and it is with this type of knitting machine that the twist imparting means of the present invention will be described.

The twist imparting means includes a rotatable member for alternately twisting the' yarns Y-l and Y-2 together in first one direction and then in the opposite direction as the yarns are fed through the feed finger l0 and to the hooks of the needles N so that the yarns are alternately twisted together in opposite directions in the stitch loops of the successive courses of the prefabric, as illustrated in FIG. 9. The twist imparting means comprises a support bar 49 fixed to the lower surface of the bridging member 32 and a circular hub 50 supported for rotation in the support bar 49. A reinforcing plate 52 is fixed to the lower surface of the bar 49, FIG. 7, and ball bearings 53 and 54 support the hub 50 for rotation. Any desired number of yarn guide openings 55 may be provided in the central portion of the hub 50 for directing individual yarns therethrough and to the single yarn guide opening or eye in the yarn feed finger 10.

Three yarn guide openings 55 are illustrated in FIG. 8 with the yarns Y-l and Y-2 extending through two of these openings. Three yarn guide openings 55 are provided in the event it may be desirable to alternately twist three yarns in one direction and then in the opposite direction. Of course, a greater or lesser number of yarn guide openings may be provided in the hub 50, if desired. A sprocket 51 is fixed on the lower end of the hub 50, FIG. 7.

Opposite ends of a sprocket drive chain are suitably connected to the inner ends of respective springs 61, 62, the outer ends of which are connected to spring perches 63 which are in turn fixed on a support bracket 64. The support bracket 64 is supported on any suitable portion of the knitting machine, such as the support arm 41. The medial portion of the chain 60 is engaged by the sprocket 51 and imparts rotation to the hub 50 in opposite directions as the support bar 49 moves'back and forth along the needle beds 11, 12. Thus, as the switch cam plates 15, 16 move from right to left in FIG. 6, the hub 50 will be rotated in a clockwise direction to impart twist to the yarns Y-l and Y-2 above the hub 50 in one direction and beneath the hub 50 in the opposite direction so that the yarns Y-l and Y-2 will be twisted together in one direction as they are knit into the prefabric. When the switch cam plates l5, l6 reach the opposite end of the knitting machine, and then move from left to right in FIG. 6, the hub 50 will be rotated in a counterclockwise direction to impart twist in the yarns Y-l and Y-2 between the hub 50 and the yarn feed finger 10 in the opposite direction so that during the knitting of this couse, the direction of twist of the yarns in the prefabric will be reversed. With this twist imparting means, exactly the same number of turns of twist in each direction will be imparted to the yarns as they are knit in the prefabric. When the prefabric is unravelled, the alternately twisted yams may be easily separated and taken up in separate packages.

A specific but nonlimiting example will be given of one type of space-dyed yarn which has been produced in accordance with the present invention. Yarns Y-l and Y-2, each being 1,150 denier, were simultaneously fed to the feed finger of a Universal 3 cut V-bed machine which has three needles in each inch of each of the needle beds 11, 12. With a 1% inch diameter sprocket 51 and knitting a fabric width of 27 inches, the yarns Y-l and Y-2 are twisted together 5.9 turns with each movement of the hub 50 from one end to the other of the fabric and while knitting one course of the prefabric.

It is to be understood that the present invention is not limited to use with specific yarn sizes and machines mentioned. Also different amounts of twist can be inserted as the yarns are knit to form the prefabric. For example, the number of turns of twist can be changed by merely changing the size of the sprocket 51.

In the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

That which is claimed is:

l. A method of producing space-dyed yarns comprising the steps of:

a. forming a prefabric by weft knitting a pair of yarns in plated relationship in each stitch loop of successive courses and while continuously twisting the yarn together in one direction during the knitting of alternate courses and continuously twisting the yarns together in the opposite direction during the knitting of intervening courses so that the yarns periodically change positions in a regular manner in the knit prefabric,

b. applying color to selected areas of the prefabric,

c. heat-setting the prefabric, and

d. unravelling the knit fabric while separately taking up each yarn of the pair to produce space-dyed yams of uniform quality.

2. A method of producing spaced-dyed yarns for use in tufted carpets and the like comprising the steps of:

a. simultaneously knitting a pair of yarns and forming b. applying color patterns to the knit fabric, c. heat-setting the knit fabric, d. unravelling the knit fabric while separating the pairs of yarns to produce space-dyed yarns of uniform quality, and

e. separately taking up the space-dyed yarns. 

1. A method of producing space-dyed yarns comprising the steps of: a. forming a prefabric by weft knitting a pair of yarns in plated relationship in each stitch loop of successive courses and while continuously twisting the yarn together in one direction during the knitting of alternate courses and continuously twisting the yarns together in the opposite direction during the knitting of intervening courses so that the yarns periodically change positions in a regular manner in the knit prefabric, b. applying color to selected areas of the prefabric, c. heat-setting the prefabric, and d. unravelling the knit fabric while separately taking up each yarn of the pair to produce space-dyed yarns of uniform quality.
 2. A method of producing spaced-dyed yarns for use in tufted carpets and the like comprising the steps of: a. simultaneously knitting a pair of yarns and forming successive courses of stitch loops while continuously twisting the pair of yarns together in one direction during the knitting of alternate courses and then continuously twisting the yarns together in the opposite direction during the knitting of intervening courses so that the yarns are alternately twisted together in opposite directions in the knit fabric, b. applying color patterns to the knit fabric, c. heat-setting the knit fabric, d. unravelling the knit fabric while separating the pairs of yarns to produce space-dyed yarns of uniform quality, and e. separately taking up the space-dyed yarns. 